Conventionally, waste water like the liquid effluent leaving a sceptic tank is treated in a mechanically aerated treatment plant, or in soil or sand absorption systems. In the former case, the installation and operation costs of the system are high and limiting. In the latter case and to be efficacious, the absorption systems require a large surface of land which is not available for everyone. Furthermore, some soils with high ground-water tables or with low permeability characteristics are not favourable for use as an absorption field.
An alternative system for treating on-site the waste water is thus required in these areas.
Known in the art for this purpose are filtering systems comprising peat-containing modules or other adapted filtering media. With these systems, the liquid effluent is pumped into the modules, distributed at low pressure over the peat, filtered through the same while it is treated by naturally occurring microorganisms or by other chemico-physical phenomena. Tile liquid emerging from the modules is a "treated" liquid which can be dispersed into a shallow bed and then into surrounding soils or eliminated by dilution in a water stream.
As can easily be understood, it is desirable that the waste water treatment system be properly ventilated and aerated to ensure aerobic treatment within the modules and also to prevent the formation of a pressure gradient in the filtering means, which would slow the filtering process and affect its efficiency. For a better efficacy of the treatment system, it is also desirable to distribute the waste water over the full surface of each module. In this regard, it is desirable that the waste water to be treated be split or divided in equal volumes while the water still has a high energy. With this approach, there is no need to rigorously make the distribution system level as it is installed. This approach also prevents accumulation of biomass on the distribution device harmful to the flow division of the waste water. Furthermore, it is also desirable that the waste water treatment system be very simple and rapid to install and maintain.